An author who accuses American scientists of faking research, igniting wars, and deliberately starting a measles epidemic among a primitive tribe of South Americans has rewritten significant sections of his controversial new book. In the finished version of Darkness in El Dorado, which will be officially published tomorrow by W. W. Norton & Co., Patrick Tierney retreats from some of the astonishing charges he leveled in pre-publication galleys and in an excerpt that ran in The New Yorker last month. This follows a wave of criticism that included my own article in National Review and a statement last week by the National Academy of Sciences saying, "Although Darkness in El Dorado gives the appearance of being well researched, in many instances the author's conclusions are either contradicted or not supported by the references he cites."

Yet Tierney continues to charge American scientists with waging "ethnocide" and "ethnographic cleansing" against the Yanomamo. This evening, he will appear in San Francisco at the American Anthropological Society convention in what is sure to be a rambunctious, standing-room-only forum.

The most important changes to Darkness in El Dorado occur at the conclusion of chapter five. Previously, Tierney claimed that in 1968 a group of researchers led by the University of Michigan's James Neel and including the renowned anthropologist Napoleon Chagnon had gone into the jungle with the purpose of infecting the Yanomamo with the deadly measles virus in order to test their social-Darwinist ideas. Tierney's shocking claim rests on the fact that the scientists carried with them a live-virus measles vaccine known as Edmonston B. Tierney says the vaccine didn't inoculate the Yanomamo, an immune-depressed population, but instead caused a measles outbreak that killed hundreds or thousands of people. He writes that Neel "sometimes sounded scarily enthusiastic about the epidemic." He quotes John Earle, a University of Pittsburgh medical historian: "I wouldn't rule out a deliberate attempt to create an epidemic." He asks Mark Papinia of the Centers for Disease Control whether Edmonston B could have set this chain of death in motion; Papinia responds, "Sure, it's possible."

In the finished version of the book, however, the line about Neel's supposed enthusiasm is gone. So is the Earle quote. And the statement by Papinia — who complained loudly that Tierney had misquoted him — is modified. Yet Tierney remains incredibly disingenuous, even with these cuts. "It is unclear whether the Edmonston B became transmissible or not," he writes. That's just not true. As many medical professionals have pointed out, there has never been a documented case of a live-virus measles vaccine like Edmonston B resulting in a transmissible disease, despite hundreds of millions of vaccinations. Never. Tierney's whole theory of this particular measles outbreak among the Yanomamo rests on the notion that it happened there, in the remote rainforest, for apparently the first time in recorded history.

Careful scientists like Papinia refuse to say that such a transmission won't ever happen; they know it's almost impossible to prove a negative. It takes reckless smear artists like Tierney to make that gigantic leap of faith. "The simplest explanation may be…that one of the vaccines, in spite of all previous expectations, became infectious," he writes. Actually, this isn't the simplest explanation; it's the most outlandish. And then Tierney essentially lies: "I am happy to leave this epidemiological puzzle to medical historians." No, he's not. If that were the case, Tierney, a journalist who calls himself a human-rights activist, would defer to the specialists. He does no such thing. Just about anybody with expertise in the area disagrees with him. Yet he plugs away, trying to bury his deceptions beneath an aura of reasonableness. (Yesterday, the Pittsburgh Post-Gazette quoted Tierney explaining, pathetically, "Experts I spoke to then had very different opinions than the ones they are expressing in public now.")

There are other changes, too. In one passage, for instance, he no longer calls Neel a "eugenicist"; now he's a "geneticist." (Later, however, he still refers to Neel's "openly eugenic views.") Tierney also backs off a charge, made in the galleys, that Chagnon was a draft dodger: "Chagnon got a draft deferment [during the Vietnam War]…Chagnon has never discussed his decision to avoid the draft." In the book, Tierney changes his tune: "Chagnon, who was a married graduate student as the Vietnam conflict began, also continued his studies during the war." And Tierney tones down, slightly, a passage in which he lambastes Chagnon's documentary films about the Yanomamo. In the galleys, he writes, "Critics who garlanded these pictures really underestimated the artistry involved. They gave blue ribbons to the greatest snuff films of all time." In the book, the films are now said to have "the feel of unintended snuff films."

Darkness in El Dorado is a disgrace. Its errors are so egregious that almost nothing between its covers can be trusted. Patrick Tierney has behaved shamefully in writing it; Norton has acted in bad faith by publishing it, even in this modified form. The subtitle of the book is How Scientists and Journalists Devastated the Amazon. The book is, in fact, an example of journalism trying to devastate science.